Peg Perego car seat

After tons of back and forth, we are finally setting down on the Peg Perego Primo Viaggio car seat, however we are confused about the difference between 2 versions - I am wondering if anyone have better knowledge?

The Nido has a bigger anti-rebound bar (the big plastic piece near the feet of the baby and the canopy that extends further down to almost cover the entire top of the seat. We used the regular PV 4-35 and worked just fine. Make sure to get another base for your spouses/grand parent's vehicle.

I used the 4-35 for both kids. I did not have a second base, and I never had a time when I found I needed it.
My daughter out-grew it in 10 months. My son outgrew it in 8 months.
We did not need car seats in the second car until the kids started day care at 12 months.